Rocket projectile with spreadable empennage



5 Sheets-Sheet 1 March 23, 1965 R. APoTHELoz ROCKET PROJECTILE WITH SPREADABLE EMPENNAGE Filed July 16, 1962 March 23, 1965 R. APo'rHELoz ROCKET PRoJEcTILl-z WITH SPREADABLE EMPENNAGE:

3 Sheets-Sheet 2 Filed July 16, 1962 March 23, 1965 R. APoTHELoz 3,174,430

ROCKET PROJECTILE WITH SPREADABLE EMPENNAGE Filed July 16, 1962 3 Sheets-Sheet 3 Fig. lf

United States Patent O 3,174,430 RCKET PROHEC'IILE WHTH SPREADABLE EMPENNAGE Robert Apothloz, Walliseilen, Zurich, Switzerland,

assigner to Machine Tool Works Gerliken, Administration Company, Zirrich-erlikon, Switzerland Filed duly 16, 1962, Ser. No. 210,115 Claims priority, application Switzerland, duly i9, 1961, 8,467/61 3 Claims. (Cl. IGZ-Sil) The invention relates to a rocket projectile, the spreadablc fins of which are swung out, after having left the launching tube, by displacing a plunger within a cylinder space by means of a source of power, and wherein a propulsive gas duct is arranged between the cylinder space and the combustion chamber of the rocket.

With Ia known rocket projectile of this kind the plunger actuating the empennage is fully loaded immediately after the ignition of the propulsive charge, which constitutes the source of power, by the pressure of the gases iiowing from the combustion chamber through the propulsive gas duct. This has the consequence that the spreadable ns coupled with the plunger are pressed with great force on the inner wall surface of the launching tube, while the rocket passes through the same, whereafter they can perform the swinging movement into the operative position under the pressure of this plunger, after having left the tube. This pressing of the tins against the wall surface of the tube involves a frictional force hampering the movement oi the rocket, .and is detrimental to fins made of synthetic materials of low strength, it constituting a danger to them.

Moreover it has become known for projectiles tired from a ire arm to let two oppositely directed forces act on a plunger coupled with the spreadable fins. One of these forces, is dependent on the gas pressure prevailing in the tiring barrel which acts on the rear end of the plunger protruding from the bottom of the projectile and which keeps the empennage retracted while a spring abutting the bottom of the projectile tends to force the plunger rearward against the gas pressure. After leaving the tiring barrel, owing to the ceasing of the action of the gas pressure, the plunger is pushed rearward by the action of the spring, and thereby the iins of the empennage are swung into the operative position. Since in the launching tube for rocket projectiles normally there prevails no appreciable pressure, this known arrangement is accordingly not applicable to rocket projectiles.

With another type of projectile to be tired from a fire arm, a cavity in the plunger opening forwardly is in spatial communication through a bore with the combustion chamber of the tiring barrel. The frontal end of the plunger has a larger diameter than its rear end. The cylinder space, wherein the plunger is housed, is provided at its rear portion with a bore, through which in the tiring position of the plunger the cylinder space is likewise in communication with the interior of the ring barrel. After the projectile has left the barrel, owirlg to appropriate dimensioning of the two bores, the portion of the cylinder space behind the frontal portion of the plunger is discharged more rapidly than the cavity of the plunger so that by the expansion of the gases still present in the cavity of the plunger the latter is forced back into that position, in which the tins are spread out.

Since in normal rocket projectiles to which the invention relates, which are to be started from launching tubes, the combustion of the propulsive charge is still in progress when the projectile leaves the tube, such an arrangement cannot be applied to rocket projectiles by supplying gases from the combustion chamber when eX- ternal pressure is lacking since the pressure yet prevailing CII S'MAS@ Patented Mar. .23, 1965 ice behind the frontal portion of the piston would prevent the swinging out of the fins immediately leaving the launching tube, as required for stabilisng the projectile.

The present invention has the object of providing a rocket projectile to be launched from a launching tube land having a spreadable empennage of tins retracted before the launching, which combines the advantages of the projectiles previously known for being fired from the barrel of a fire arm or from a launching tube, while obviating their disadvantages. It is a particular object of the invention to provide a rocket projectile of this kind, the tins of which contact the inner walls of the launching tube only with a weak force at the firing and while passing through said launching tube, and are spread out rapidly immediately after the projectile has left said launching tube.

With these .and other objects in View which will become apparent later from the following specification and accompanying drawings, I provide a rocket projectile for launching from a launching tube, comprising in combination: Ia combustion chamber, a cylinder arranged at the rear end of said combustion chamber co-axially therewith, a plunger slidably mounted in said cylinder, power means including a propellant charge in operation generating propulsive gases operatively acting on said plunger, iins coupled to said plunger arranged at the rear end of said combustion chamber pivotally about axes perpendicular to the axis of said combustion chamber and having a retracted position parallel to said axis and a spread-out position forming an empennage of said rocket projectile, said cylinder having a iirst propulsive gas duct at a point of its circumference in communication with said combustion chamber Iand covered at least partly by said plunger in the retracted position of said fins coupled therewith, and cleared by said plunger after the beginning of the spreading movement of said tins initiated by said power means immediately after the launching of said rocket projectile from said launching tube.

These and other features of my said invention will be clearly understood from the following description of a preferred embodiment and of some modifications thereof, given by way of example with reference to the accompanying drawings in which:

FIGURE l is 4a cross-sectional view of the rear end of .a rocket projectile taken upon section line I-l of FIG'URE 3.

FIGURE 2 is a cross-sectional View taken upon section yline II-II of FIGURE l.

FIGURE 3 is a cross-sectional View taken upon section line III-III of FIGURE 1.

FIGURE 4 is an elevational view with parts in section illustrating the rear end of the rocket projectile after being launched from a tube.

FIGURE 5 is a cross-sectional view of a detail illustrating a modification.

FIGURE 6 is a similar View illustrating a further modification, and

FIGURE 7 is a similar view illustrating a still further modification.

The forward portion of the cylinder 6 projecting into the combustion chamber I is provided with a bore 15 forming the propulsive gas duct, which connects accordingly the combustion chamber with the space of the cylinder 6. The bore i5 issues into the cylinder space at a point of the circumference thereof covered by the plunger 13 at the moment of firing. At the rear end of the plunger 13 projecting from the carrier 7, arms 16 are fixed, on each of which, as shown also in FIGURE 3, two guide discs 17 lare iitted, between which engage the forward edges 11a of the tins 11. In the retracted position of the empennage, the rear edges of the arms form abutments for the tins 1I. These abutments are located at points having a smaller distance from the axis of the rocket than the pivot axes of the ins 11. The force of the spring 14 transmitted by the arms 16 acts on the empennage in the sense of spreading the same, the tins of the empennage being kept retracted in the rest position by a dished plate 18 surrounding their rear ends.

The function of this arrangement follows from its construction: when tiring the rocket, the plunger 13 and the tins 11 coupled with it are in the position shown in FIG- URE l. After igniting the propulsive charge 3 the dished plate 18 is thrown ofr" by the gases emerging from the nozzles S, so that the tins 11 contact the inner wall surfaces of a launching tube under the action of the weak force of the spring 14 transmitted through the plunger 13. The plunger 13 keeps the bore 15 for the gas closed at the firing and during the passage of the rocket through the launching tube. After the rocket has left that tube, the movement of the plunger 13, and accordingly the spreading of the tins 11 is initiated by the bias of the spring 14 serving as a source of power, which moves the plunger back, firstly so far, that it completelyV clears the bore 15. Under the pressure of the gases then iiowing from the combustion chamber 1 into the cylinder space, the plunger 13 is moved back with a reinforced power. Thereby the tins 11 are swung outwardly very rapidly into the operative position (FIGURE 4). The movement of the fins 11 is delayed before reaching their end position by the inertia forces engaging on them generated by the acceleration of the rocket, so that the impact yof their edges llc` on the flange 8a of the sleeve is damped. The plunger 13 in its rear position abuts with its shoulder 13a a complementary shoulder 9a of the bore 9, and moreover the arms 16 abut with their faces 16a the edges 11b of the tins 11 which edges in this position are directed parallel to the longitudinal axis of the rocket, whereby these tins are xed in their operative position.

In the FIGURES to 7 further embodiments of the plunger and cylinder areshown :as modifications of the above embodiments. For example, FIGURE 5 shows a second propulsive gas duct connecting the combustion chamber with the cylinder space which is formed by a bore 19 machined into the forward end wall of the cylinder. This bore has a smaller diameter than the bore 15, and cannot be obturated by the plunger. gases tiowing upon firing through this second propulsive gas duct from the source of power to the cylinder ahead of the plunger 13 are throttled so strongly that they exert a force which is considerably smaller than the force generated by the plunger when fully spreading the fins.

For the same purpose as this throttle bore 19, a groove 20 or 21 may be provided, which either runs according to FIGURE 6 in the wall of the cylinder 6 parallel Vto the cylinder axis, or is cut into the surface of the plunger 13 as according to FIGURE 7. Since this groove 20 or 21 owing to its small cross sectional area establishes communication between the combustion chamber and the cylinder space to a small extent only, the force initially acting on the plunger is likewise smaller than after such communtcation is completely cleared.

In the embodiment according to FIGURE l the plunger is held and secured in its end position by the spring 14 after the termination of the combustion and fading out Thel of the gas pressure. In the embodiments according to FIGURES 5 to 7, for example, the conical shoulder 13a -of the plunger may be made with such an `aperture angle that it is held self-locking in its seat 9a.

While I have herein described, and illustrated in the Iaccompanying drawings what may be considered typical and particularly advantageous embodiments of my said invention, I wish it to be understood that I do not limit myself to the particular details and dimensions described yand illustrated; for obvious modifications will occur to a person skilled in the art.

What I claim as my invention and desire to secure by Letters Patent, is:

l. A rocket projectile to be tired from a tube, comprising a carrier secured to the rear end of said projectile, a combustion chamber located in front of said carrier, a cylinder arranged on said carrier projecting into said combustion chamber, control means including a plunger slidably mounted in said cylinder, power means including a propellant charge in operation generating propulsive gases operatively acting on said plunger, fins coupled to said plunger mounted on said carrier pivotally about axes perpendicular to the longitudinal axis of said projectile, said tins when in a retracted position extending parallel to said axis and when in a spread-out position extending outwardly at an angle to said axis, said cylinder having a `irst propulsive gas duct at a point of its circumference in communication with said combustion chamber controlled by said plunger of said control means in said retracted position of said ns coupled therewith, and cleared by said plunger of said controlmeans after the beginning of the spreading movement of said-fins initiated by said power means immediatelyrafter the launching of said rocket projectile from said tube.

2. A rocket projectile as claimed in claim l, wherein said power means-includes further -a compression spring .arranged in said cylinder between the bottom thereof and said plunger and biasing the samel rearwardly at a force weaker than the force exerted by t-he pressure of said propulsive gases on Vsaid plunger after the latter has cleared said -first propulsive gas duct which is completely closed in the retracted position of said n's..

-3. A rocket projectile as claimed in claim 1, compris- .ing a second propulsive gas duct 'permanently connecting -said combustion chamber with said cylinder, said second propulsive gas duct being of a cross sectional 4area substantially smaller than saidfirst propulsive gas duct, the

latter being completely closedin the retracted position of said tins.

References Cited by the Examiner UNITED STATES PATENTS SAMUEL FEINBERG, Primary Examiner.

ARTHUR M. HORTON, Examiner. 

1. A ROCKET PROJECTILE TO BE FIRED FROM A TUBE, COMPRISING A CARRIER SECURED TO THE REAR END OF SAID PROJECTILE, A COMBUSTION CHAMBER LOCATED IN FRONT OF SAID CARRIER, A CYLINDER ARRANGED ON SAID CARRIER PROJECTING INTO SAID COMBUSTION CHAMBER, CONTROL MEANS INCLUDING A PLUNGER SLIDABLY MOUNTED IN SAID CYLINDER, POWER MEANS INCLUDING A PROPELLANT CHARGE IN OPERATION GENERATING PROPULSIVE GASES OPERATIVELY ACTING ON SAID PLUNGER, FINS COUPLED TO SAID PLUNGER MOUNTED ON SAID CARRIER PIVOTALLY ABOUT AXES PERPENDICULAR TO THE LONGITUDINAL AXIS OF SAID PROJECTILE, SAID FINS WHEN IN A RETRACTED POSITION EXTENDING PARALLEL TO SAID AXIS AND WHEN IN A SPREAD-OUT POSITION EXTENDING OUTWARDLY AT AN ANGLE TO SAID AXIS, SAID CYLINDER HAVING A FIRST PROPULSIVE GAS DUCT AT A POINT OF ITS CIRCUMFERENCE IN COMMUNICATION WITH SAID COMBUSTION CHAMBER CONTROLLED BY SAID PLUNGER OF SAID CONTROL MEANS IN SAID RETRACTED POSITION OF SAID FINS COUPLED THEREWITH, AND CLEARED BY SAID PLUNGER OF SAID CONTROL MEANS AFTER THE BEGINNING OF THE SPREADING MOVEMENT OF SAID FINS INITIATED BY SAID POWER MEANS IMMEDIATELY AFTER THE LAUNCHING OF SAID ROCKET PROJECTILE FROM SAID TUBE. 